<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>第一个three.js文件_WebGL三维场景</title>
    <style>
        body {
            margin: 0;
            overflow: hidden;
            /* 隐藏body窗口区域滚动条 */
        }
    </style>
    <!-- 引入三维引擎 -->
    <script src="../external/three-js-r93/build/three.js"></script>
    <!-- 扩展控件 OrbitControls -->
    <script src="../external/three-js-r93/examples/js/controls/OrbitControls.js"></script>
</head>

<body>
<script>
    /**
     * 创建场景对象Scene
     */
    var scene = new THREE.Scene();
    /**
     * 创建管道网格模型
     */
        //创建管道成型的路径(3D样条曲线)
    var path = new THREE.CatmullRomCurve3([
            new THREE.Vector3(-10, -50, -50),
            new THREE.Vector3(10, 0, 0),
            new THREE.Vector3(8, 50, 50),
            new THREE.Vector3(-5, 0, 100)
        ]);
    // LineCurve3创建直线段路径
    // var path = new THREE.LineCurve3(new THREE.Vector3(0, 100, 0), new THREE.Vector3(0, 0, 0));
    // TubeGeometry对2D曲线支持不太好
    // var path = new THREE.LineCurve(new THREE.Vector2(0, 100), new THREE.Vector2(0, 0));
    // path:路径   40：沿着轨迹细分数  2：管道半径   25：管道截面圆细分数
    var geometry = new THREE.TubeGeometry(path, 40, 2, 25);
    // 控制台查看的TubeBufferGeometry结构
    // console.log(geometry.attributes.position);
    // console.log(geometry.index);
    var material = new THREE.MeshPhongMaterial({
        color: 0x0000ff,
        side: THREE.DoubleSide //两面可见
    }); //材质对象
    // material.wireframe = true;//线条模式渲染(查看细分数)
    var mesh = new THREE.Mesh(geometry, material); //管道网格模型对象
    scene.add(mesh); //管道网格模型添加到场景中
    /**
     * 光源设置
     */
        //点光源
    var point = new THREE.PointLight(0xffffff);
    point.position.set(400, 200, 300); //点光源位置
    scene.add(point); //点光源添加到场景中
    //环境光
    var ambient = new THREE.AmbientLight(0x444444);
    scene.add(ambient);
    /**
     * 相机设置
     */
    var width = window.innerWidth; //窗口宽度
    var height = window.innerHeight; //窗口高度
    var k = width / height; //窗口宽高比
    var s = 150; //三维场景显示范围控制系数，系数越大，显示的范围越大
    //创建相机对象
    var camera = new THREE.OrthographicCamera(-s * k, s * k, s, -s, 1, 1000);
    camera.position.set(200, 300, 200); //设置相机位置
    camera.lookAt(scene.position); //设置相机方向(指向的场景对象)
    /**
     * 创建渲染器对象
     */
    var renderer = new THREE.WebGLRenderer();
    renderer.setSize(width, height); //设置渲染区域尺寸
    renderer.setClearColor(0xb9d3ff, 1); //设置背景颜色
    document.body.appendChild(renderer.domElement); //body元素中插入canvas对象

    // 渲染函数
    function render() {
        renderer.render(scene, camera); //执行渲染操作
    }
    render();
    //创建控件对象  相机对象camera作为参数   控件可以监听鼠标的变化，改变相机对象的属性
    var controls = new THREE.OrbitControls(camera);
    //监听鼠标事件，触发渲染函数，更新canvas画布渲染效果
    controls.addEventListener('change', render);
</script>
</body>

</html>
